I usually think of these as feminine: touching lips with my fingers, running my hand though my hair, exposing wrists, self-touching on the neck/thigh. These are the ones that come to mind at present.
You're always going to want to maintain dominant body language. She might expose her wrists or neck, you might monitor you posture to appear similar to hers, but keeping your palms down rather than turning them up. Yeah, you could probably brush your hair back in unison or, best, echo the action some time later. Touching your neck might be just a quick scratch instead of a soft massage which a woman might tend to do. You want to pick up the macro-movements and blur them a bit so they don't seem copy-cat or monkey-see-monkey-do. By macro I mean stuff like resting the elbow on the bar top if she does, taking a drink at the same time, and stuff like that.
So in short, do as she does, except if it's overly submissive. Do a dominant twist on the body language instead and mirror the action of the gesture, rather than the specific gesture itself. You're trying to dance in unison, and when people dance, there are still masculine and feminine roles. If you can take the lead...now that's the real objective, have her follow...